Floor structure for a test chamber

ABSTRACT

A test chamber having a floor including a flexible sealing diaphragm secured to a frame removable and insertable laterally through an open door together with an exterior vibrating unit adapted to transmit vibrations through the diaphragm.

on..- ma [151 3,664,181

Conrad et a]. 51 May 23, 1972 [54] FLOOR STRLpl um run A u: 3,121,3352/1964 Ongaro ..73/460 CHAMBER 3,241,358 3/1966 Booth et al. ..73/7 1 .6

[72] Inventors: Charles F. Conrad; Kieth L. Dadd, both of OTHERPUBLICATIONS Holland, Mich.

David, B. R., Furnace on a Shaker," M. B. Vibrations [73] Assignee:Thermotron Corporation, Inc., Holland, Notebook, Vol. 9, No. 4, Dec.,l963,pp 1-4 Mich.- Fairchild, Space Environments Laboratory Publication,

' t S 4- 36 Filed: y 1968 Receiveda PatentOffice ept 27 1963 pp 6 [21 1AppL 747 5 Primary Examiner-Richard C. Queisser AssistantExaminer-Arthur E. Korkosz Attorney-Glenn B. Morse 52 u.s,c| ..73/7'1.6,73/432 [51] Int. Cl. ..G01n 29/00 57 ABSTRACT [58] Field ofSearch..73/7l.5,7l.6,7l.7,432 SM,

73/150 460 15 A test chamber having a floor including a flexible sealingdiaphragm secured to a frame removable and insertable laterally throughan open door together with an exterior [56] References Cited vibratingunit adapted to transmit vibrations through the UNITED STATES PATENTSdiaphragm- 3,049,9l3 8/1962 Hunt ..73/71.6 10 Claims,6DrawingFiguresPATENTED AY2 I97E 3,664,181

SHEET 1 UF 2 25 INVENTORS Charles F. Conrad BY Kieth L. Dodd ATTORNEYllllllllllllll lllllllll l lllllllllllllllll ll SHEET 2 OF 2 \gww mlllll lllfllllllllllllllllnblrll 5 z IIIIIIIIIIIIIIIIIIIIIIIIIIII llPATENTEDMAY as me INVENTORS horles F. Conrad BY Kieth.L. Dodd lIIIIIIIIIIII II ATTORNEY FLOOR STRUCTURE FOR A TEST CHAMBER BACKGROUNDTest chambers have come into very wide use in recent years in the courseof the development of instruments and equipment installed in ahigh-altitude aircraft and space vehicles. This equipment necessarilymust function properly in an environment including very low airpressure, extremes of temperature, and conditions of severe vibration. Asealed chamber of relatively conventional construction can easily beequipped to provide the extremes of temperature 'and atmosphericpressure, or can provide any other sort of gaseous environment that maybe desired. A problem is encountered, however, when a vibration programis added. If the vibration generator is included within the chamber, thesize of the chamber becomes prohibitive. The design of the vibratingequipment must also accommodate the very extremes of environment thatare being produced in the test chamber. Both of these factors contributeto a technical problem as well as a problem in economics.

Arrangements have been tried for positioning the vibration generatorexteriorly of the sealed test chamber, with provision for thetransmission of vibrations through some portion of the walls of thechamber. Various developments in this direction have been noted in thefollowing references:

Reference Patent No. Date MB Vibrations Notebook Volume 2, No. l, Pages7-9 1956 Thompson-Houston (French) L239, l 93 1960 Hunt (United States)3,049,9[3 1962 Taccogna'(United States) 3,l42,l72 1964 Booth et al.(United States) 3,24l,358 1966 SUMMARY OF THE INVENTION in the preferredform of the invention, exposes the entrance to T the guideways. Once theunit is moved into position, the closing of the door can generate asealing engagement between the door and the floor unit. Preferably, thefloor structure is clamped upwardly against the test chamber on a gasketto improve the seal around the periphery.

The disengageable floor of the test chamber is defined by a framepreferably constructed of foamed plastic insulating material overlayedby a flexible diaphragm seal capable of transmitting vibrations with aminimum of transmission over to the structure of the frame and thechamber walls. The vapor-tight sheet of flexible material constitutingthe diaphragm can be fiberglass cloth impregnated with silicone rubber,or other materials having similar characteristics. It is oftenpreferable to use a flexible laminated sheet combining the effects of avapor-tight seal with some degree of insulation. The insulating laminacan be polyurethane foam in most in stances.

In order to supply the test equipment within the chamber, it is usuallynecessary to provide conduits for electricity, gas, or other materials.These conduits are admitted through passages in the floor frame whichare preferably defined by flexible sleeves equipped with drawstringswhich can be gathered together around the conduits after installation,and thus maintain a seal around them.

DESCRIPTION OF THE DRAWINGS The several features of the invention willbe analyzed in detail through a discussion of the embodiment illustratedin the accompanying drawings. In the drawings:

FIG. 1 is a perspective view showing a test chamber with the floor unitremoved.

FIG. 2 is a perspective view of the floor unit, from above, on anenlarged scale.

FIG. 3 is a perspective view of the unit shown in FIG. 2, from below.

FIG. 4 is a side elevation showing the installed relationship of thefloor unit, the vibrating device, and the adjacent chamber structure.

FIG. 5 is a sectional elevation on an enlarged scale showing thepreferred form of the conduit passage construction.

FIG. 6 shows an installed conduit, with the drawstring of the passagesleeve constricted around it for sealing.

DESCRIPTION OF THE PREFERRED EMBODIMENT The test chamber generallyindicated at 10 in FIG. 1 has a hinged door 11 defining what amounts toone side of the test enclosure. This door may be swung to the right toclosed position, as viewed in FIG. 1, followed by engagement of thelatch 12. The chamber structure includes the opposite angle-shaped rails13 and 14, the horizontal flanges of which provide sup port for thefloor unit generally indicated at 15. This unit may he slid in from theleft, as viewed in FIG. 1, with the rails 13 and 14 respectivelyreceiving the edges 16 and 17 of the floor unit. After this unit hasbeen shoved in place, auxiliary clamping devices (not shown) can beincorporated to force the floor unit 15 upwardly preferably against asuitable perpheral gasket for obtaining the best possible seal closingoff the interior of the test chamber against leakage. The horizontalorientation of the rails 13 and 14, and the fact that the door 11 swingsopen to a sufficient degree to completely expose the side of the testchamber, make it possible to install the floor unit 15 as it rests ontop of the conventional vibration-generating unit 18 in the manner shownin FIG. 4. The seal between the floor unit and the adjacent portions ofthe chamber structure may be affected around the periphery of the top ofthe floor unit, at the vertical faces defining the edge of the floorunit, or a combination of these. In FIG. 4, the door 11 closes againstthe edge of the floor unit 15, and the remainder of the chamber issealed to the floor unit around the top surface of the floor unitthrough standard suitable clamping devices (not shown). It isconceivable that a sufiiciently close dimensional relationship may existbetween the height of the vibrating unit 18, the thickness of the floorunit 15, and the position of the lower edge 19 of the chamber structureabove the floor 20 to permit the unit to merely be rolled into placewithout auxiliary clamping devices for producing a sealed relationship.

The structure of the floor unit is best shown in FIGS. 5 and 6. Arectangular frame 21 is constructed primarily of foamed plastic materialsuch as polyethylene, polyurethane, or polystyrene, which is usedprimarily for lightness and insulating characteristics. The frame 21 ispreferably reinforced by a metal channel 22, and the opening 23 definedby the frame 21 is covered by the flexible diaphragm 24. This diaphragmmay be of fiberglass cloth impregnated with silicone rubber, or othersimilar materials which are highly flexible, and provide a vapor-tightseal under the particular conditions encountered during the testproject. In the construction illustrated in FIG. 5, the diaphragm 24 isa single sheet secured to the frame by the clamping angle 25 held inposition by the fastenings 26. A gasket 27 of standard material isinterposed between the top surface of the floor unit 15 and theunderside of the wall of the chamber structure 10.

One or more vertical passages are formed in the material of the frame21, and these are traversed by flexible sleeves as shown at 28-31 toprovide sealable passages for receiving conduits as shown at 32 in FIG.6. These sleeves may be of the same sort of flexible material as thediaphragm 24, and the preferred form has a surrounding tubular portion33 at the lower end for receiving a drawstring 34. The sleeves aresecured on the inside by sealing the flaps 30 H to, the diaphragm 24with adhesive. After the conduit 32 has been installed for the supply ofthe equipment being tested, the drawstring 34 can be pulled togethertightly to seal off the interior of the chamber against leakage. Ifdesired, this form of seal may be supplemented (or replaced) by stuffingthe passage in the frame 21 with foam or potting material around theinstalled conduit.

The supporting panel forming the table-like surface of the top of thevibration generator 18 may be of any desired material. FIG. 4 shows theuse of a laminate supporting surface 35, but this forms no part of thepresent invention. The frame 21 surrounds the supporting panel 35, butthere should be sufficient clearance between the periphery of the panel35 and the frame 21 to permit the vibrations to be generated withouttransmitting them directly over to the frame 21. Vertical movement, ofcourse, is transmitted directly upwardly through the flexible diaphragm,and requires very little side clearance.

The particular embodiments of the present invention which have beenillustrated and discussed herein are for illustrative purposes only andare not to be considered as a limitation upon the scope of the appendedclaims. In these claims, it is our intent to claim the entire inventiondisclosed herein, except as we are limited by the prior art.

We claim:

1. A test chamber including an enclosure structure with a floor having aflexible sealing diaphragm, in combination with a vibrating unitdisposed below said diaphragm and adapted to transmit vibrations throughsaid diaphragm to articles within said enclosure structure, wherein theimprovement comprises:

a frame defining an opening in said floor normally receiving a supportportion of said vibrating unit, said diaphragm extending across saidopening and being supported at least in part on said support portion,said frame having at least one conduit passage normally receivingsealing means surrounding conduit means traversing said passage.

2. A test chamber as defined in claim 1, wherein said sealing means is aflexible sleeve in alignment with said passage.

3. A test chamber as defined in claim 2, wherein said sleeve traversessaid passage, and includes constricting means exteriorly of saidpassage.

4. A test chamber as defined in claim 1, wherein said enclosurestructure includes door means in a side thereof. and

5 guideways substantially nonnal to the plane of the opening l0 anddisengageable horizontally through the opening defined by the openposition of said door means, said floor frame being in closely fittingrelationship with the surrounding structure of said enclosure in theclosed position of said door.

6. A test chamber as defined in claim 1, wherein said frame isconstructed of reinforced insulating material, and normally surroundsthe support portion of said vibrating unit.

7. A test chamber as defined in claim 1, wherein said diaphragm is alaminate including sealing and insulating laminae.

8. A test chamber as defined in claim 1, wherein said frame defines theentire bottom of said enclosure structure.

9. A test chamber including an enclosure structure with a floor having aflexible sealing diaphragm, in combination with a vibrating unitdisposed below said diaphragm and adapted to transmit vibrations throughsaid diaphragm to articles within said enclosure structure, wherein theimprovement comprises:

a frame defining an opening in said floor normally receiving a supportportion of said vibrating unit, said diaphragm extending across saidopening and being supported at least in part on said support portion;and

door means in a side of said enclosure structure, said enclosurestructure also having guideways substantially normal to the plane of theopening covered by said door means,

said guideways receiving cti pposite edges of said frame. 10. A testchamber as e med in claim 9, wherein said guideways are horizontal, andsaid floor frame is engageable and disengageable horizontally throughthe opening defined by the open position of said door means.

II III i i

1. A test chamber including an enclosure structure with a floor having aflexible sealing diaphragm, in combination with a vibrating unitdisposed below said diaphragm and adapted to transmit vibrations throughsaid diaphragm to articles within said enclosure structure, wherein theimprovement comprises: a frame defining an opening in said floornormally receiving a support portion of said vibrating unit, saiddiaphragm extending across said opening and being supported at least inpart on said support portion, said frame having at least one conduitpassage normally receiving sealing means surrounding conduit meanstraversing said passage.
 2. A test chamber as defined in claim 1,wherein said sealing means is a flexible sleeve in alignment with saidpassage.
 3. A test chamber as defined in claim 2, wherein said sleevetraverses said passage, and includes constricting means exteriorly ofsaid passage.
 4. A test chamber as defined in claim 1, wherein saidenclosure structure includes door means in a side thereof, and guidewayssubstantially normal to the plane of the opening covered by said doormeans, said guideways receiving opposite edges of said frame.
 5. A testchamber as defined in claim 4, wherein said guideways are horizontal,and said floor frame is engageable and disengageable horizontallythrough the opening defined by the open position of said door means,said floor frame being in closely fitting relationship with thesurrounding structure of said enclosure in the closed position of saiddoor.
 6. A test chamber as defined in claim 1, wherein said frame isconstructed of reinforced insulating material, and normally surroundsthe support portion of said vibrating unit.
 7. A test chamber as definedin claim 1, wherein said diaphragm is a laminate including sealing andinsulating laminae.
 8. A test chamber as defined in claim 1, whereinsaid frame defines the entire bottom of said enclosure structure.
 9. Atest chamber including an enclosure structure with a floor having aflexible sealing diaphragm, in combination with a vibrating unitdisposed below said diaphragm and adapted to transmit vibrations throughsaid diaphragm to articles within said enclosure structure, wherein theimprovement comprises: a frame defining an opening in said floornormally receiving a support portion of said vibrating unit, saiddiaphragm extending across said opening and being supported at least inpart on said support portion; and door means in a side of said enclosurestructure, said enclosure structure also having guideways substantiallynormal to the plane of the opening covered by said door means, saidguideways receiving opposite edges of said frame.
 10. A test chamber asdefined in claim 9, wherein said guideways are horizontal, and saidfloor frame is engageable and disengageable horizontally through theopening defined by the open position of said door means.